The issue of pornography

Some exciting news: Mr. Grilled Cheese has emailed an update for “Love Letters: The Results Show,” which will run the first week in October. It’s going to take some serious self-control on my part not to post his update until then. But I’m all about self-control.
Today’s letter is about pornography, an issue that came up in our chat last week. Be careful with your comments so they don’t get censored (family website, etc.).
Here we go:

Hi Meredith,
Last week my live-in girlfriend came home late from work and totally blew up because she thought she had caught me watching porn.
She was wrong -- I wasn't watching porn -- but was angry nonetheless. I admitted to her long ago that watching porn is something that I do. She admitted in the past that she can't keep up with my sex drive. I'm faithful, don't frequent strip clubs, and wouldn't even consider touching another woman. I am happily committed. My girlfriend is a wonderful woman with an amazing body and we have a great sex life; I just like to supplement it when she's not around or not in the mood.
What is it about porn that some women have such an issue about? What can I do to convince her that my behavior is normal, doesn't change how I think or feel about her, doesn't indicate a desire to stray, and doesn't negatively impact our sex life?

– Porn is the Norm, Metrowest

PITN, I’ve angered a number of Love Letters readers in the past with my opinions about pornography.
For the record: I’m not an anti-porn person. I’m a whatever-floats-your-boat-within-reason person.
I’m pretty sure that some people watch porn for the same reason I read “Twilight” – or for the same reason my mom is such a big fan of the show “House” – or for the same reason my sister used to watch “The Lost Boys” on a loop after she hit puberty. I mean, we all consume media that takes us to another place or puts us in a particular mood. I don’t think there’s anything wrong with that.
Of course, that doesn't mean your girlfriend's feelings are wrong. They're her feelings, after all. If you were refusing to be intimate with your girlfriend but sought out porn, she would have reason to feel rejected. If the type of pornography you were watching made her uncomfortable – if she believed it to be degrading or violent – her negative feelings would be understandable, right?
My point is: your girlfriend's objection to pornography may not be about porn in general. It's possible that she’s uncomfortable with something specific about your routine.
You need to have a real talk about her feelings. Find out what bothers her. Perhaps you’ll learn something new. Perhaps it’s not at all what you think.
You need to be just as honest and explain what it does for you and why. Your defense shouldn’t be “Everybody's doing it!” That’s just confrontational and won't get you anywhere.
If she’s anti-porn across the board and that’s just how she feels, it’s up to the two of you to see if you can find a compromise. Relationships are all about compromise, right? Even when it comes to this.
Readers? Any advice about compromising when it comes to pornography? Share your G-rated thoughts here, please. And send me letters to the right, of course.